1. Field of the Invention
The present invention relates to a curable resin composition and to a molded article produced by molding the curable resin composition. Further, the invention relates to a method for producing the molded article. In particular, the invention relates to a curable resin composition useful for production of optical parts.
2. Description of the Related Art
Heretofore, a curable resin composition has been employed for producing optical parts such as lenses, etc. The curable resin composition to be used here is injected into a mold or the like, cured and molded therein. A curable resin composition, of which cure shrinkage is reduced by incorporating thereinto a polymer having a polymerizing group and referred to as a prepolymer, is known.
As the curable resin composition of the type, known are those described in Patent Document 1 and Patent Document 2. The curable resin composition described in Patent Document 1 uses an urethane resin as the resin ingredient therein. The curable resin composition described in Patent Document 1 shrinks little in curing, has good mold releasability and is excellent in scratch resistance, and is further excellent in long-term stability at 60° C. However, the composition has a problem in that its water absorption is high.
On the other hand, Patent Document 2 describes a curable resin composition containing an adamantyl acrylate. The curable resin composition described in Patent Document 2 has high transparency. However, it has a problem in that the glass transition temperature (Tg) thereof is low.